<template>
  <div>
    <h4>第四题</h4>
    <button @click="btn">点击</button>
  </div>
</template>

<script>
export default {
  methods: {
    btn() {
      function copy(target) {
        // ...在这里补充代码
        return [...target]
      }
      let arr = [1, 2, 3, 4, 5];
      let brr = copy(arr);
      arr.push(100);
      console.log(brr); // [1, 2, 3, 4, 5]
    },
  },
};
</script>

<style scoped>
</style>